Polyonax alticornis Dinosaur: Polyonax alticornis Period Details Status: S > Triceratops alticornis Autor: Cope Year: 1889 Classification Other References: E. D. Cope. (1889). The age of the Denver Formation. ________________________ If you are interested in Excel Professional version of Dinosaur or Pterosaur Database, write to us Facebook Twitter LinkedIn Tumblr VKontakte Odnoklassniki Pocket Skype Messenger Messenger WhatsApp Telegram Viber Line Share via Email